1996 mercury promax 225

[storm5]

im new to the site so forgive me im trying to figure it out. but i have a mercury 225 promax. it has 25 hours on full rebuild. ive replaced almost every thing on this motor. the ecm, stator, rectifiers, switchbox, high pressure fuel pump, injectors have been sent out and been cleaned and flow tested. the reason im selling the motor is to upgrade to a optimax and as of right now the promax will not spin over 4100 rpm and the mercury dealer here cant figure it out. but the motor runs perfect until that rpm. im sure its a small fix just no one around here can figure it out. so it being a sick promax im asking $5000 or best offer im located in jacksonville florida. thanks

[storm5]

or how about this shoot me an offer if interested.

[malibu4440]

who did the rebuild and do have any photos

[storm5]

Presision powerhead of jacksonville,fl and i will get some pics in a few days

[malibu4440]

photos ?

[storm5]

Im getting photos as soon as i get into town. And i will post them on here

[malibu4440]

Pleasecall 352-283-4797 thanks

[storm5]

I finally got pictures so if your interested and want pics please pm me thanks

[Screwedup]

What gearcase?

[storm5]

the stock promax gearcase. it does not have the nose water pic-up if that helps. send me a pm i can give you a pic.

[gerry 56]

I'm in Orlando and interested in your motor. Please give me a call 407-456-1507. Thanks, Gerry.

[storm5]

Will call tomorrow thanks

[whipper]

Pulse pump. 15 bucks and 10 min to replace diaphragm,spring and gasket. The springs get weak and can feed the demand to the VST tank so when you reach 4000 rpm you have drained the VST tank and its only filling it up enough for a lesser demand. Ive had to change mine 3 times in 10 years did the same thing. Great idleing because it has a chance to fill the VST. then great at take off because the vst was full to start. then as i go the demand is greater and the VST tank drains. no fuel no power. Mine is also a 96 225 promax. i just updated the cowl and decals.

[storm5]

Thank you so much for the info i will try that and update you. Again thank you and ill get that put in this weekend

[storm5]

Whipper the low side fuel pump dident work. Still same symtom. But i have a hand full of parts that im replaceing on it that are known good parts and we will see how that goes.

[whipper]

Yes its hard to pin point what the problem is when ya replace more than one thing at a time. but regardless as long as the problem gets fix is better than not. and you know have a lot of new parts on there.. Ive done the same thing. Hope that was it.:cheers:

[tux974]

Yes, sometimes pinpointing or finding the actual problem can be a bit difficult and extremely frustrating especially if you do not do this on a regular bases. I see you have changed plenty of parts, at this point I suggest to find someone that is familiar with these motors to help you even if you need to travel a bit.
gerry56 in Orlando or Diamond Marine 954 525 2600 in Lauderdale are very familiar with these motors give them a call maybe they can help you! You may need to make the trip though....GL and report back your findings so we all learn from things like this.

Tony

[Flatlander]

Piston in upside down? I've seen it happen and those are the symptoms...it won't spin up

[storm5]

I will update about the motor and what i find. And the pistons are all in the correct positions and have been checked by a mercury dealer. Its just sometging small and stupid with the motor. And i only replace one part at a time to pin point the problem so i will be able to report on what it actually was. Just finding the time to take it back and forth to the ramp to water test is the biggest pain. But thank you for the replys.

[props4u2]

Have you replaced the fuel line and primer bulb? Or even tried to run it with a remote fuel tank an fuel line.

[gerry 56]

I had messaged you about possibly purchasing the motor a while back. If you are wanting to keep it, I would be happy to try to help you fix it at no charge. I live in Orlando and maybe we could meet halfway or something. Just let me know, Gerry 56. 407-456-1507

[storm5]

Ive ran a remote tank and all new lines and primer bulb. And same symptoms. Its something on the motor. Gerry did we talk? And i will take any help i can get. If you know allot about these motors i wouldnt mind driveing down to you for the help. And if your still interested in it its still forsale..

[gerry 56]

We never did talk and I have already purchased another motor. But I will be happy to help you fix your motor. I sell packaging and shipping supplies and I travel all the way to Palm Coast - Ormond Beach area to see customers. If you want I could meet you around that area on a week day that might be convenient for you. No charge, just trying to help and it will be worth more after it's fixed! Just give me a call and we can take care of it. Gerry 56. 407-456-1507 (tel:407-456-1507)

[tux974]

We never did talk and I have already purchased another motor. But I will be happy to help you fix your motor. I sell packaging and shipping supplies and I travel all the way to Palm Coast - Ormond Beach area to see customers. If you want I could meet you around that area on a week day that might be convenient for you. No charge, just trying to help and it will be worth more after it's fixed! Just give me a call and we can take care of it. Gerry 56. 407-456-1507 (tel:407-456-1507)

That is a very generous offer!!
It does not get any better then that, awesome site here!!

[Go Time]

What are the comression numbers?
WOT timing? Are the idle contorl and oil injection alarm modules removed? how about the temp sensors and TPS? all these can affect timing and WOT.

[storm5]

Gerry thank you very much i will be getting in contact with you soon. Compression is 125 across all 6 cyl and 10% leak down on every one also. Mercury has gone over the timeing and throttle position sensor they say that all is good and right on. It still has the oil injection and the alarm module is new.tps is also new and was calabrated correctly. Temp sensors i have not done anything with yet nor have they been checked

[Laser LTV]

We never did talk and I have already purchased another motor. But I will be happy to help you fix your motor. I sell packaging and shipping supplies and I travel all the way to Palm Coast - Ormond Beach area to see customers. If you want I could meet you around that area on a week day that might be convenient for you. No charge, just trying to help and it will be worth more after it's fixed! Just give me a call and we can take care of it. Gerry 56. 407-456-1507 (tel:407-456-1507)Gerry is a great guy to deal with and has nice stuff too

[motorheadbishop]

High side of the Stator go bad???

[storm5]

Two new stators put on and a known good one is on it now.... and the high side of the stator went out and thats how this all happened

[Sleek Jr]

I'm not sure where to ask, but all this makes me want to ask about a similar situation on two older carb Mercs I have, an 80 V200 and 88 XR4 150. Compression is around 100-110 on all six, on both. The V200 used to turn 6000-6200 with a 21 pitch, and now only 4600, same prop and boat. It's lost about 1500 RPM. I removed the idle and high speed advance module. It's getting plenty of fuel. New lines, bulb, pump, and even put an inline electric pump
to make sure it was not running out of fuel. Carbs and jets have been gone through and were completely clean.

Sometimes, at a given throttle setting at cruise (around 3500-4000), it's like something will "Kick In" and it will take off for a brief second, and gain 300-500 RPM, but
then go right back to the lower RPM. The motor has been rebuilt, but all electrical is original.

I apologize if I'm hijacking the thread (let me know if I am cuz I'm not sure what that term means.. but have an idea) but storm5 's problem was the first one I've run
across similar to my own, and I had just given up on it until reading his post.

[badbob76087]

What you asking for it running poorly?

[TEXAS20225]

what happened to yours Bob on the Bullet

[badbob76087]

what happened to yours Bob on the Bullet

Sold it with Laser, ran that 28 pitch chopper you sold me at 6100 rpm.

Way too noisy with all the exhaust cut out and relief holes.

Thinking about a 250 but like old school.

[TEXAS20225]

i just sold a 250 i wont have another 3.0 on my bullet im building some trick 225 pmaxs now

[badbob76087]

i just sold a 250 i wont have another 3.0 on my bullet im building some trick 225 pmaxs now


Let me know, what you getting for them? Can I put one under my 2.5 150XRi cover?

[storm5]

I would like for the promax sick ive got a ton of parts ill let go with it. Stator,trigger, high low fuel pump,stock computer, the list goes on.

[Ziemer]

Can you email me some pics? jmartindesignz@yahoo.com

Thanks,
Jeff

[xskeetshooter]

have you ever had it running good rpm's under load since u owned it?
i bought a motor that did the same thing....one of the mechanics at the marine dealer stole the lower unit off n stuck a unit on with the wrong lu gears....
put o reg lower unit on it and it ran perfect....

[storm5]

I will email pics and yes it ran perfect. Til the high side stator went out then had all the trouble.

[TEXAS20225]

what ecm is extra

[gerry 56]

I messaged you beginning of March about helping you fix your motor. If your wanting to sell now just let me know. I'm in Orlando and I could just come pick it up and pay cash. Give me a call when you can. Thank you, Gerry 407-456-1507

[TEXAS20225]

hmmmmm high side winding went would not twist past 4100 fixed high side windings and it still would not wind past 4100 is this the situation??? i build a lot of efi power heads every year and lots of different troubles show up on these things if a bad stator has been replaced and same situation exist how accurate is the stator diagnosis

[whipper]

Did you try a differant ecu? i also remember a mechanic was meddling with my TPS and had it all out of wack! It wouldn't turn up until it was dialed right. Wouldnt it be funny if your link and sink wasnt full throttle. When you have your foot to the floor are your butterflies wide open? haha You know what its got to be something easy because it starts! you need to bring it to another mechanic that knows these things inside and out. Because any decent merc racing mechanic should figure this out in a day. Any drag racers with 2.5 motors near by? Those guys can smell whats wrong with it a mile away! One drive and they will know ill bet.

[storm5]

Gerry i will call you soon and for everyone else. There ave been 3 different stators and triggers put on same result.. the ecm is a stock one that came with the motor and have two of them. The tps is new and set up corrextly. The throttle opens all the way up. That was the first thing i checked... its got to be something small and stupid with this... it starts and runs great.... sorry for the delay in messages

[motorheadbishop]

Gerry i will call you soon and for everyone else. There ave been 3 different stators and triggers put on same result.. the ecm is a stock one that came with the motor and have two of them. The tps is new and set up corrextly. The throttle opens all the way up. That was the first thing i checked... its got to be something small and stupid with this... it starts and runs great.... sorry for the delay in messages

We have a motor doing the exact same thing... Did you ever figure it out???

[aggiestckl]

We have a motor doing the exact same thing... Did you ever figure it out???
I thought you guys only had 300 drags, s3000s and fire breathing 280s

[jpickett]

Did u ever sell the Promax?

[storm5]

I still have the motor.

[storm5]

Well as of today the promax is not sick anymore and is all fixed up and ready to roll. If anyone is interested in it let me know price has changed a little but pm me about it... and for everyone who asked questions to help me out thank you... and it ended up being a combonation of things from fuel pump to fuel pressure regulator tps air temp sensor basically the whole intake and vst tank i removed it and put one on from a known running motor and 2 known good switch boxs and it ran like the promax it was... again thanks to all the great ppl on scream and fly that offered there time to help and give segestions..

[J.R.]

is it a 20 or 25"

[storm5]

20" mid